Energy scientist studies blackout triggers

When an electrical power grid is operating close to capacity, small fluctuations can easily trigger a blackout, said Benjamin Carreras, a physicist at Oak Ridge National Laboratory in Oak Ridge, Tenn.

Carreras has been working for several years on computer simulations of the behavior of the power grid. He was finishing a paper on his research when the Aug. 14 blackout hit large parts of the northeastern United States and the Canadian province of Ontario.

Carreras and his collaborators at the universities of Wisconsin and Alaska have examined 15 years' worth of data on blackouts of sections of the U.S. power grid.

Because power demands have been growing faster than the grid itself, it operates close to critical points that trigger a cascading power outage, Carreras said. His model resembles a sand pile in which sand is being added to the top, grain by grain. The particles do not roll off one by one, however, but slide off in small and large avalanches.

The research could improve understanding of the general conditions that start the cascades, to keep future blackouts from spreading, he said.

Carreras and his collaborators wrote their simulations in C++ and are running them on single-processor workstations. He said he hopes to develop larger-scale models that would run on parallel supercomputers.